NGK 3923 Spark Plug

NGK BPR8ES Standard Spark Plug Overview

The NGK 3923 standard spark plug is built for OE-style ignition performance in a wide range of classic import applications. It uses a copper center electrode, nickel tip materials, and a standard ground design to support consistent spark delivery and dependable combustion.

As part of the NGK Standard Spark Plug line, this plug reflects the brand’s long OE supply background and focus on original-equipment-style durability for everyday service needs. It is a practical choice for drivers searching for an NGK BPR8ES spark plug for Porsche 911 or Maserati Biturbo applications.

Key Features

• NGK part number 3923, also identified as BPR8ES
• Standard spark plug design for OE-equivalent replacement service
• Copper center electrode core for stable ignition transfer
• Nickel center and ground electrode tip materials
• 5000 ohm resistance for ignition system noise suppression
• Pre-gapped at .032 inch
• 14 mm thread diameter, .75 inch reach, flat seat
• 13/16 hex size with removable nut terminal

Detailed Description

NGK 3923 is a standard replacement spark plug engineered for vehicles that call for the BPR8ES specification. Its copper core and nickel electrode construction support reliable spark delivery, while the standard ground configuration and flat seat match common OE-style service requirements. This makes it a direct-fit option for owners looking for a Porsche 911 spark plug or a Maserati 430i spark plug with the correct heat range and gap specification.

Compatible With 1970-1973 Porsche 911, 1974-1977 Porsche 911, 1981-1984 Porsche 911, 1985-1989 Porsche 911, 1974-1975 Porsche 911, 1974 Porsche 911, 1983-1987 Maserati Biturbo, and 1989-1990 Maserati 430i. This part cross-references Autolite 3923 for the same application.

What It Helps Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle from inconsistent ignition output
• Misfire conditions related to plug wear or incorrect gap
• Reduced throttle response from weak spark delivery
• Service replacement needs for OE-style ignition maintenance

Installation Notes and Tips

Verify the vehicle’s required heat range, thread size, reach, seat type, and gap before installation. The listed pre-gap is .032 inch, but some applications in the fitment data specify OEM gaps such as 0.024 or 0.028 inch for Porsche 911 and Maserati models, so confirm the exact specification for your engine before use. Inspect plug wires, coils, and terminal condition during service to help maintain consistent ignition performance.

Quality Assurance

NGK is a long-established OE supplier with extensive North American coverage for domestic and import ignition applications. The 3923 spark plug is produced to support original-equipment-style durability and operational consistency across the listed Porsche 911 and Maserati applications.